Epistolary Librarian

Free-spell payoffs usually gate their power behind a build-around cost: an artifact count, a graveyard, a coin flip. This one prices its cheating in bodies. Swing wide and the mana value you can dump onto the stack for free scales one-for-one with how many creatures joined the attack: four attackers means a four-drop cast without paying for it, on the trigger, during the declare-attackers step. That timing is the sharpest part. The spell resolves before blockers are declared, so a mass pump, a removal spell, or another attacker-generating threat lands while the combat math is still soft, letting you reshape a swing your opponent thought they had answered. The 3/4 body is a deliberate governor: it wants to attack every turn, but it is not so large that it survives being blocked into indefinitely, which keeps the payoff tethered to a real go-wide board rather than a single evasive creature carrying the trigger alone. Read it as the go-wide deck's cost-reduction finisher: the more the aggressive plan is working, the bigger the free spell, and the closer to zero the marginal cost of the next threat. It is a payoff that rewards the exact thing the deck was already trying to do, then compounds it mid-combat.